Pet Insulin Outside the Fridge: What Every Label Publishes, and the One Number None of Them Do

If the power has been off since yesterday, the refrigerator is no longer cold and there is a vial in the door that a cat or dog depends on twice a day, the label is the first thing to read. What it says depends on the product.

If the vial says Vetsulin or ProZinc, the insert does not answer the question. The two insulins FDA-approved for pets publish no out-of-fridge allowance, and neither label mentions heat. If the vial or pen says Lantus, Basaglar, Semglee, Rezvoglar, Langlara, Toujeo or Tresiba, the insert publishes a number, but it is capped at 86°F (30°C), a temperature an unconditioned house in July can pass, and the document was written for a person, not your animal. In either case, call the veterinarian who prescribed it.

This page does not tell you whether the vial in your hand is still good. That is a judgment about one animal’s vial, and no veterinarian reviews this site. Where a label or manufacturer publishes a disposition for a defined exposure (several do, for freezing), we report it as theirs.

Three points where careful people go wrong:

The product list has moved. The current veterinary authority for cats is the 2026 AAHA Diabetes Management Guidelines for Cats, published April 26, 2026. Its insulin product table names Lente, Glargine U-100, PZI, Degludec and Glargine U-300, and does not name detemir. The 2018 AAHA guideline it replaced does the opposite: it has a detemir row, does not mention degludec or Tresiba, and treats U-300 only as a concentration of glargine to avoid. A feline insulin list that still includes detemir is drawn from the older document.

“Glargine” is not one product. Eight current US glargine labels from five labelers are cited here, and they disagree on how many in-use days they allow and on whether a product may be refrigerated in use.

A day count without its temperature ceiling is half a fact. Every human in-use figure below is a room-temperature figure capped at 86°F (30°C).

What This Page Will Not Do

It publishes no dose, dose conversion, substitution of one insulin for another, schedule, hour count for a warmed vial, or judgment that a product is or is not still usable. Those decisions belong to the veterinarian who prescribed the insulin and the pharmacy that dispensed it. Where a source carries such an instruction, we name it and leave it where it is.

That boundary follows the evidence. The makers of the two pet-approved products publish no out-of-fridge tolerance, so there is no number to report. The makers of the human products publish one, but bound it at a temperature and address it to a patient who checks their own blood glucose.

The Two Products Approved for Pets Publish No Out-of-Fridge Answer

Vetsulin (Merck Animal Health)

Vetsulin is porcine insulin zinc suspension (lente), U-40, indicated for dogs and cats with diabetes mellitus and approved under NADA number 141-236. The entire storage section of the current label (SPL version 8, published July 3, 2025) reads:

“Store in an upright position under refrigeration at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.”

A sentence follows saying a loaded VetPen may be stored on its side, then: “Use contents within 42 days of first puncture.” There is no room-temperature row, no excursion allowance, no maximum time outside the range and no instruction for a night at 80 degrees.

The 42 days is often repeated as if it were an out-of-fridge number. It is not. It is in-use dating from the first needle puncture, sitting under an instruction to keep the vial refrigerated the whole time. It says when a properly stored, punctured vial stops being current. It says nothing about a vial that got warm.

An older Vetsulin insert on vetsulin.com (revision marker 02/13) gives the same instruction. Merck’s owner FAQ gives the range as 2°C to 8°C (35°F to 46°F) instead of 36°F. The Celsius figures match, so the gap is a Fahrenheit conversion. The FDA-approved label says 36°F. A household should treat the tighter range as the target.

Merck’s owner FAQ also answers the question the insert leaves alone:

“Vetsulin should always remain refrigerated. If you accidentally leave a vial out of the refrigerator, contact your veterinarian for instructions.”

On freezing, it says freezing damages the insulin molecules and reduces efficacy, and that a vial that froze in the refrigerator should be discarded and replaced. Its “what else should I know” bullets include “Always have a spare vial on hand” and “If it has gotten too hot, or frozen, discard it immediately”. The second is the only discard-on-heat instruction we found from a maker of either pet-approved product, and it sits on an owner FAQ, not in FDA-approved labeling. How large a spare to keep, and how to time the refill, is the prescriber’s decision.

ProZinc (Boehringer Ingelheim Animal Health)

ProZinc is protamine zinc recombinant human insulin, U-40, approved under NADA number 141-297. Its current label (SPL version 11, published January 24, 2025) contains a package insert and client information sheet for cats and for dogs. All carry the same instruction, though not typed identically: store upright under refrigeration at 36-46°F (2-8°C), “Do not freeze. Protect from light.”, and

“Use the 10 mL vial within 60 days of first puncture. Use the 20 mL vial within 80 days of first puncture.”

As with Vetsulin, those are in-use clocks for a refrigerated vial, not out-of-fridge allowances.

The mixing instructions are opposite. ProZinc says in capitals not to shake or agitate the vial and to roll it gently; Vetsulin says to shake until the suspension is uniform. Both are correct for their own product.

What is missing from both labels

As of the label versions above, neither Vetsulin’s nor ProZinc’s label contains the words heat, discard, room temperature, excursion, unrefrigerated, warm or “out of the refrigerator”. The word “excessive” appears, but only for clinical signs of diabetes or causes of hypoglycemia, never for storage. The old vetsulin.com insert has the same gaps.

So “discard if exposed to excessive heat”, which circulates as if it were label language for these products, is not in either FDA-approved label. Boehringer Ingelheim’s ProZinc canine page says only that ProZinc requires refrigeration and U-40 syringes; its feline page has no storage or temperature language. We found no comparable discard-on-heat sentence for ProZinc from its maker.

No out-of-fridge tolerance for these two products appears in either label, the old insert, Merck’s owner FAQ, Boehringer Ingelheim’s product pages, or current AAHA guidance for either species. That is a statement about the documents in this page’s source list, not everything ever published.

The Human Insulins, and Why “Extralabel” Matters

Diabetic cats in the United States are commonly treated with a human insulin. That is standard veterinary practice, not improvisation, and the guideline says so. No figure for how many cats is published in anything we used, so none is given here.

The 2026 AAHA feline guideline (section 7) says the most common choices for cats remain glargine U-100, approved for people, and PZI, approved for cats and dogs. It also says Lente (Vetsulin) is approved for and often used in cats, but task force members do not routinely recommend it as a first-choice insulin because its duration of action is shorter. Our reading, not the guideline’s: that is why a cat owner may hold a human carton rather than a veterinary one, and why a page about pet insulin storage cannot rest on the two veterinary labels alone.

The guideline’s Table 7.1 has a column headed “Veterinary FDA Approval Status”. Vetsulin and ProZinc are marked “Approved”. Lantus, Basaglar, Semglee, the unbranded Biocon glargine, Rezvoglar, Tresiba and Toujeo are marked “Not approved”.

The federal term

The governing regulation is 21 CFR Part 530, titled EXTRALABEL DRUG USE IN ANIMALS. Section 530.3(a) defines the term as

“actual use or intended use of a drug in an animal in a manner that is not in accordance with the approved labeling.”

That includes use in species not listed in the labeling, and a human insulin in a cat is exactly that. Section 530.10 permits such use

“By or on the lawful written or oral order of a licensed veterinarian within the context of a valid veterinarian-client-patient relationship”

and section 530.11 lists as not permitted extralabel use of an approved human drug by a lay person, except under a veterinarian’s supervision. (eCFR states title 21 was current as of 8/18/2026.)

Two things follow. An extralabel prescription is ordinary and not a sign that anything is irregular. And the authority for how that drug is used in that animal is the veterinarian, not the carton, which was written for a different species. Our page on finding veterinary care mid-evacuation works the same Part 530 framework from the other end.

Not one word about animals

A text search of all ten human insulin labels cited here (eight branded, two unbranded) found no occurrence of veterinar, feline, canine or pet. Cat and dog appeared only inside unrelated words such as indication, medication and category. The word animal appears only in the pregnancy and nonclinical sections, describing studies in rats and rabbits. So when a human insulin carton gives 28 days at room temperature, that is a statement about a human patient’s supply, from a maker never asked about your cat.

What Each Issuer Publishes

Every cell is what that product’s current label states. Where a label does not address something, the cell says so. Nothing is averaged or inferred across issuers.

Read the ceiling with every number. Every room-temperature figure in the human rows is capped at 86°F (30°C) by the label that publishes it. Where a row also permits refrigeration in use, that is for 36 to 46°F and is a different condition. Above 86°F, none of these figures describes the storage condition any more.

Product (issuer)	Molecule and strength	Unopened, refrigerated	Unopened, room temperature (up to 86°F [30°C])	In use, after first puncture or first use	Freezing	Label published
Vetsulin (Merck Animal Health)	Porcine insulin zinc suspension, U-40	Upright at 2°C to 8°C (36°F to 46°F), protect from light	Not addressed	42 days from first puncture, refrigerated throughout	Do not freeze; no disposition on the label	Jul 3 2025
ProZinc (Boehringer Ingelheim)	Protamine zinc recombinant human insulin, U-40	Upright at 36-46°F (2-8°C), protect from light	Not addressed	60 days (10 mL vial) or 80 days (20 mL vial) from first puncture	Do not freeze; no disposition on the label	Jan 24 2025
Lantus and Lantus SoloStar (Sanofi-Aventis U.S.)	Insulin glargine, U-100	Until expiration date	28 days	Vial: 28 days refrigerated or room temperature. SoloStar pen: 28 days room temperature only, do not refrigerate	Discard if frozen	Jul 2 2025
Basaglar KwikPen and Tempo Pen (Eli Lilly)	Insulin glargine, U-100	Until expiration date	28 days	28 days, room temperature, do not refrigerate; no refrigerated in-use column	Storage section: do not freeze. Instructions for Use: do not use if frozen	Aug 10 2026
Semglee (Biocon Biologics)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Vial: 28 days refrigerated or room temperature. Pen: 28 days room temperature only	Discard if frozen	Apr 17 2026
Insulin Glargine-yfgn, unbranded (Biocon Biologics)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Vial: 28 days refrigerated or room temperature. Pen: 28 days room temperature only	Discard if frozen	Aug 17 2026
Insulin Glargine-yfgn (Civica)	Insulin glargine-yfgn, U-100	Until expiration date	28 days	Pen only: 28 days, room temperature only	Discard if frozen	Nov 17 2025
Rezvoglar KwikPen (Eli Lilly)	Insulin glargine-aglr, U-100	Until expiration date	28 days	28 days, room temperature only; cumulative (see note)	Discard if frozen	Aug 19 2024
Langlara (Lanexa Biologics)	Insulin glargine-aldy, U-100	Until expiration date	28 days	Pen only: 28 days, room temperature only	Discard if frozen	Jul 8 2026
Toujeo and Toujeo Max SoloStar (Sanofi-Aventis U.S.)	Insulin glargine, U-300	Until expiration date	Not a separate cell; one unopened column, refrigerated	56 days, room temperature only, with a cap-on condition in the cell	Discard the prefilled pen if frozen	Jun 12 2025
Tresiba (Novo Nordisk)	Insulin degludec, U-100 and U-200	Until expiration date	56 days (8 weeks)	56 days (8 weeks), refrigerated or room temperature, all three presentations	Do not use if frozen	Jul 20 2022
Levemir (Novo Nordisk)	Insulin detemir, U-100 (see the discontinuation section)	Until expiration date	42 days	Vial: 42 days. FlexPen: do not refrigerate in use; 42 days at room temperature	Do not use if frozen	Dec 29 2025

Rezvoglar’s footnote. Its storage table says that at room temperature the KwikPen can be used for a total of 28 days counting both unopened and opened storage time. Without that footnote its 28-day cell reads like Lantus’s and means something different. For Lantus and most others, opening starts a fresh clock. For Rezvoglar at room temperature, the clock has been running since the pen left the refrigerator.

Toujeo’s condition. Its in-use cell says

“always store the prefilled pens with the cap on during in-use period.”

followed by the room-temperature-only instruction and the 86°F ceiling.

Scope. The table covers the storage sections of currently posted US labels for the insulins named in the 2026 AAHA feline product table, their unbranded twins, and detemir. It is not a list of every insulin and does not include NPH, regular insulin or mixes. It states storage only: no dose, duration of action, or indication of which product suits which animal.

What the table shows

The presentation decides the refrigeration answer, not the molecule. Glargine U-100 in a 10 mL vial may be refrigerated or kept at room temperature in use on the Lantus, Semglee and unbranded Biocon labels, the three of the eight that supply a vial. Glargine in a pen may not be refrigerated in use on any of the eight glargine labels. Same molecule, same strength, opposite instruction, decided by the container. That is our reading of the tables lined up, not a sentence any label writes.

The day count splits 28 against 56, and the split is real. U-100 glargine publishes 28 days, Toujeo (U-300) 56, Tresiba 56, Levemir 42. They are different formulations, and an average would describe nothing.

Two of the twelve rows carry a condition inside the cell that changes the answer: Rezvoglar’s cumulative clock and Toujeo’s cap-on requirement.

The 86°F Ceiling

If you take one number from this page, take 86, not 28 or 56.

All ten human labels print it. Lantus, Basaglar, Rezvoglar, Langlara, Levemir, Tresiba and Toujeo word it as up to 86°F (30°C). Semglee and the Biocon and Civica unbranded labels print it as up to 30°C (86°F).

Where it appears differs. Basaglar, Toujeo, Levemir and Tresiba put it over or inside the in-use column of the storage table. Lantus, Rezvoglar, Semglee, the two unbranded glargines and Langlara head their in-use column “(see temperature below)”, print the cap over the unopened room-temperature column, and state the in-use ceiling in the patient sections. Lantus puts it this way for vials: refrigerated, or

“at room temperature below 86°F (30°C) for up to 28 days.”

Our reading: a reader who checks only the table on six of these ten labels sees a day count with no temperature attached, which is how the number gets separated from its condition.

The ceiling is not a finding about how much heat insulin survives. It defines the storage condition the manufacturer’s figure was set for. A house without air conditioning in a summer outage is not a room-temperature environment in that sense. A published allowance capped at 86°F cannot be read as an allowance above 86°F, so the day counts stop answering the question exactly when it gets urgent. That is our reasoning from putting the ceiling next to the scenario.

The FDA’s emergency page for human patients uses the same ceiling: vials or cartridges from manufacturers, opened or unopened,

“may be left unrefrigerated at a temperature between 59°F and 86°F for up to 28 days and continue to work.”

The next sentence is often dropped and matters for small animals, since diluted insulin is not unusual in cats and small dogs: FDA says a product altered for dilution, or removed from the original vial, should be discarded within two weeks. A compounded or diluted product is not the product the 28 days was published about. FDA’s page also says all three US insulin manufacturers recommend storage at about 36°F to 46°F. That phrasing is out of date: as of August 19, 2026, the FDA-linked National Drug Code directory listed 23 finished insulin glargine products from five labelers plus one repackager. Read the label on your own product.

The FDA page and CDC’s Managing Insulin in an Emergency page (dated May 15, 2024) go on to address a person who has no choice but to use insulin stored above the ceiling. We do not reproduce those sentences. CDC ties its allowance to self-monitoring of blood sugar; FDA ties its allowance to keeping the insulin as cool as possible, not freezing it, and discarding and replacing exposed vials once properly stored insulin is available. Both are addressed to a human patient under their own physician, and no veterinarian reviews this site to extend them to an animal.

That is a reason about who the pages were written for, not about what a household can measure. Section 11 of the 2026 AAHA feline guideline lists Home Monitoring Options: continuous glucose monitors, a glucometer if only a veterinary-calibrated portable meter is used, and, for cats possibly approaching remission, monitoring for glucose in urine. Our medical consumables calculator for a 14 day evacuation carries that passage. Whether your animal is on any of them is a question for the practice that prescribed the insulin. FDA’s page also has an insulin-substitution table, and its own instruction there is:

“Switching insulin should always be done in consultation with a physician and requires close medical supervision”

No substitution, conversion or product swap for an animal appears on this page.

Two CDC instructions transfer because they give only a direction of travel:

“Try to keep your insulin cool, but make sure not to freeze it.”

“Keep your insulin away from direct heat and out of direct sunlight.”

Freezing: Three Kinds of Document, Three Instructions

The human labels state a disposition. Lantus says to discard it if it has been frozen, and Langlara says the same about itself. Semglee, Rezvoglar, Toujeo and both unbranded glargines carry the same construction. Levemir and Tresiba say not to use the product if frozen. Basaglar differs only in placement: its storage section says just “Do not freeze BASAGLAR.”, and the Instructions for Use for each pen add “Do not use if it has been frozen.” A reader who checks only section 16 of a Basaglar label might think it says nothing about a pen that froze.

The veterinary labels state a storage instruction and stop. Vetsulin’s and ProZinc’s labels say only “Do not freeze.” Do not freeze is an instruction about storage; discard if frozen is an instruction about what to do afterward, and the second does not follow from the first. On the veterinary side it is not on the label.

The manufacturer’s owner page carries it, for one of the two products. Merck’s Vetsulin FAQ says a frozen vial should be discarded and replaced:

“If a vial of insulin accidentally freezes in the refrigerator, it should be discarded and a new vial should be used.”

No equivalent sentence turned up for ProZinc.

The guideline states a prohibition and a replacement trigger. The 2026 AAHA feline guideline tells clients not to freeze insulin or expose it to heat, and to avoid leaving it in places prone to temperature extremes such as a parked car or direct sun. It separately says:

“If the insulin ever appears flocculent, discolored, or exhibits consistency changes, it should be replaced immediately.”

A warning about the refrigerator itself. Levemir’s storage section says not to store in the freezer or directly adjacent to the refrigerator cooling element, and Tresiba’s carries the same instruction. The back wall of a household refrigerator, against the cooling plate, freezes things, and that is a cold-side failure a household can prevent for free by moving the box.

The University of Illinois College of Veterinary Medicine post makes the transport version of the point: an ice pack can keep insulin cool on the way home, but the insulin should not touch it. It adds that frozen insulin should be discarded because of degradation, as manufacturers recommend.

You Cannot Settle This by Looking

Every product family publishes a visual accept-or-reject test. Vetsulin says not to use it if visible clumps or white particles persist after thorough shaking. ProZinc’s client sheet says not to use it and to call your veterinarian if there are clumps or visible white particles after gentle rolling. The AAHA guideline says to replace insulin that appears flocculent, discolored or changed in consistency.

Yet every heat or freeze instruction in these documents is triggered by the exposure, not the appearance. Merck’s discard bullet is conditioned on the vial having gotten too hot or frozen, with no visual condition. Lantus’s discard sentence is conditioned on the product having been frozen, not how it looks afterward.

Putting those together is our reasoning, not a sentence any document writes: the visual tests catch a suspension that has not resuspended or a solution that visibly changed. They are not offered as a test for whether a temperature exposure did damage. A normal-looking vial is not evidence that a warm night did nothing to it.

One veterinary source says it directly. The University of Illinois College of Veterinary Medicine, in a Practitioner Updates post dated July 9, 2025, says owners who use insulin past its discard date should monitor for discoloration, particulates and changes in consistency, then adds:

“They should be advised that signs of degradation may not be visible.”

Weigh it for what it is: a veterinary college blog post bylined to a fourth-year pharmacy student, citing the 2018 AAHA guideline. It is quoted because it is the only source we found that says the point plainly and is not selling a cooler. Most other pages on this claim belong to companies that sell insulin cooling cases. This site publishes an insulin cooler buying guide and earns affiliate commission on cooler recommendations, and this claim makes coolers look more necessary. That is why it is sourced to a veterinary college and the labels, and nothing in this section recommends a product.

The same post is the clearest statement we found of the human-versus-veterinary difference: opened human insulin products may be stored at room temperature or refrigerated (check the package insert), while veterinary insulins must remain refrigerated. It also says most manufacturers recommend discarding opened insulin after 28 to 60 days. That bracket covers every human row and ProZinc’s 10 mL vial but not the 80 days ProZinc gives its 20 mL vial, so read it as a summary of the category, not a figure to apply to a product.

What Veterinary Guidance Adds, and Where It Stops

Cats: the 2026 guideline

Section 11 (client education) says refrigerating insulin maintains a consistent temperature and allows extended use of each vial. When insulin is refrigerated and handled carefully, the task force is comfortable with clients using it beyond the manufacturer’s in-use duration, which it puts at 28-56 days for most insulin types. That is an extension of in-use dating, conditioned on refrigeration. It is not an out-of-fridge tolerance, and the guideline publishes none. Its bracket matches the human rows in the table but not the veterinary ones (42, 60 and 80 days), and it does not claim to.

The same passage says preservative-containing vials used for six months were not shown to carry an increased contamination risk. Then it gives the closest thing to a decision rule in current guidance:

“the task force recommends replacing the insulin vial.”

That applies if there are questions about efficacy or if the cat’s clinical signs recur despite fully compliant therapy. The trigger is the animal’s clinical picture and the owner’s doubt, not a thermometer reading or a number of hours.

Section 11 also contains hypoglycemia home-management steps. That belongs in a veterinarian’s instructions for one cat and is not reproduced here. Its routing does belong on a preparedness page: seek urgent veterinary assistance if signs of hypoglycemia are noted, and

“never increase the insulin dose or frequency of administration without clear instructions from their veterinarian.”

This page does not print the signs of hypoglycemia, because no veterinarian reviews this site. The guideline prints them for the veterinary team. Ask the practice that prescribed the insulin to write down, in their own words, which signs in your animal should send you to a clinic, and put that on the same card as their phone number. Ask before a storm season, not during one.

Two further points from section 7 change what a household should have on hand. The guideline names degludec and glargine U-300, which older guidance did not. And it warns that glargine U-300 is more concentrated but less potent than U-100 and should be treated as a separate insulin type, not simply three times U-100. Section 11 adds that some insulins, such as glargine U-300 and degludec U-200, must be given with an insulin pen. A household on one needs the pen and its needles, not only a vial in the cold.

The guideline’s product table has no storage column. Table 7.1 has seven columns (product, description, brand and manufacturer, veterinary FDA approval status, peak action and duration, starting dose, concentration) and none for storage. That observation is ours; the guideline does not comment on it. The table’s footer states it is intended as a guideline only, not an AAHA standard of care, and should not be construed as dictating an exclusive protocol.

The table is already incomplete. Under Glargine U-100 it lists Lantus, Basaglar, Semglee, an unbranded Biocon glargine and Rezvoglar. It does not list Langlara (label first published July 8, 2026) or Civica’s unbranded glargine (November 17, 2025). A guideline published April 26, 2026 cannot list a product labeled in July. The point is that the only current answer for the product in your hand is the label on it.

Dogs: still the 2018 guideline

AAHA split its diabetes guidelines by species, and only the feline half has been rewritten. The canine guidance is the 2018 AAHA Diabetes Management Guidelines for Dogs and Cats, which notes it includes updates made in 2022. A dog household and a cat household are working from different documents of different vintages.

Its client-education section is plain about storage:

“Do not freeze insulin preparations.”

“Do not expose insulin to heat; avoid leaving in parked car or prolonged exposure to direct sunlight.”

It also recommends storage in a refrigerator for consistency of environment and a new vial if insulin changes in appearance. Its Table 1 carries an approval-status column: Vetsulin reads “Dogs, cats”, Lantus “Not approved”, Levemir “Neither”. A further passage says that if insulin is stored carefully, the task force is comfortable with using it beyond the expiration date as long as it is not discolored, flocculent or changed in consistency, and recommends checking the package insert for shelf life after opening. It carries the same condition as the feline passage: careful storage first.

Detemir, and a Federal Record That Does Not Agree With Itself

Detemir has been named as a feline option in much writing, including the 2018 guideline. It is on its way out, and the paper trail is messy, so we describe it rather than pick a side.

Novo Nordisk announced on November 8, 2023 that it would discontinue Levemir, the only US detemir product, citing manufacturing constraints, reduced patient access and available alternatives. The Pediatric Endocrine Society’s drug alert lists April 1, 2024 for the FlexPen and December 31, 2024 for the vial.

As of August 19, 2026, the federal record had not fully caught up:

• The Drugs@FDA record for BLA021536 (Novo Nordisk Inc) lists LEVEMIR FLEXPEN, INNOLET and PENFILL as Discontinued, while LEVEMIR FLEXTOUCH and the 10 mL vial still read Prescription. We rechecked it September 26, 2026.
• The FDA-linked drug directory carried a marketing end date of August 31, 2026 for the vial (NDC 0169-3687).
• DailyMed still hosts a Levemir label published December 29, 2025.
• Detemir does not appear in Table 7.1 of the 2026 AAHA feline guideline.

None of that is a reason to change a prescription. It is a reason to check availability with your pharmacy before a storm season rather than during one.

The Non-Refrigerated Option Is Not an Outage Workaround

Some diabetic cats have nothing in the refrigerator at all. FDA has approved two oral, non-insulin drugs for diabetes in cats: Bexacat (bexagliflozin tablets) and Senvelgo (velagliflozin oral solution), both sodium-glucose cotransporter 2 (SGLT2) inhibitors given by mouth once daily. Neither is a refrigerated product. Bexacat’s label (SPL version 3, published May 21, 2026) gives room-temperature storage of 68 to 77 degrees Fahrenheit (20 to 25 degrees Celsius). Senvelgo’s label (SPL version 5, published April 2, 2026) allows storage at or below 77°F (25°C), with excursions permitted up to 104°F (40°C), and use within six months of opening. That is a stated ceiling, an excursion allowance and an in-use clock, which neither insulin label publishes.

What this must not become is a plan. FDA’s owner-facing page says:

“Cats that have previously been given insulin shots should not take Bexacat or Senvelgo, as these cats have a higher risk of developing diabetic ketoacidosis.”

It also says serious side effects such as diabetic ketoacidosis and pancreatitis can happen with or without warning, even with appropriate screening and close monitoring, and that careful monitoring matters however long a cat has been on the drug. So the oral option is not something a household switches to because the refrigerator failed. We make no comparison between the treatments and no recommendation about either. The AAHA feline guideline’s takeaway is that SGLT2 inhibitors are not insulin.

One preparedness step applies today. The guideline tells veterinarians to instruct clients to tell the veterinary team that their cat has diabetes and is on an SGLT2 inhibitor, which is especially important in an emergency where a complete medical record may not be available. Our pet medication log for evacuation is where to write it down. It records what was given and when without any prescriber parameter.

Questions to Ask Before Storm Season

These ask for information only the prescribing practice has, and each is easier to answer in April than during a warning.

• Which exact product is my animal on, by brand and presentation? Vial versus pen matters, and so does strength: U-100 and U-300 glargine behave differently, and U-40 veterinary products differ again.
• Is it an FDA-approved veterinary product or a human product prescribed extralabel?
• What do you want me to do if this product spends time out of the refrigerator, and how should I describe the exposure when I call?
• If it is a pen, do I have enough needles staged with it, and does it need anything a vial would not?
• Should I keep a spare vial or pen, and how would you like the refill timed? Merck’s owner FAQ tells Vetsulin households to keep a spare.
• If we lose the fridge for several days, at what point do you want me to bring the product in rather than manage it at home?
• What should an emergency clinic know about this animal in one sentence, if I arrive with no records?

Our page on emergency and early pet prescription refills covers refill timing and the veterinarian-client-patient relationship.

Your Insulin Label Checklist

• Read the storage sentence off the actual carton or insert for your exact product, by brand and presentation, and write it down.
• If it is Vetsulin or ProZinc, note that the label publishes no out-of-fridge allowance. That is the answer, and it is why the maker routes the question to your veterinarian.
• If it is a human product, write the 86°F ceiling next to the day count. The count only describes storage at or below that temperature.
• Check whether it is a vial or a pen, and whether its table says the in-use product may be refrigerated. Every glargine pen reviewed says do not refrigerate in use; the vials do not all say that.
• If you have Rezvoglar, read its footnote. If you have Toujeo, note the cap-on condition.
• Move the box away from the back wall of the refrigerator, since two labels warn against storing insulin next to the cooling element.
• Do not let an ice pack touch the vial.
• Put the manufacturer’s phone route and your veterinary practice’s number on the same card as the medication list.
• Write down what you would tell an unfamiliar clinic in one sentence, including whether your cat is on an SGLT2 inhibitor rather than insulin.
• If the product is a pen, stage its needles with it.
• Ask about a spare and refill timing before a season, not during a warning.
• Do not apply any figure here to an insulin not named on this page, and do not average two rows.
• Ask your veterinarian to write down which signs of hypoglycemia in your animal should send you to a clinic, and keep it with the medication list.
• If an exposure has already happened, call the practice that prescribed the insulin. That call is the published answer from Merck, from the current feline guideline and from this page.
• If you cannot reach that practice, keep calling, and do not stop at the call. Keep insulin cool, do not freeze it, and keep it out of direct heat and sun. Our guide to keeping pet medication cold when the power goes out covers the closed-refrigerator clock, the cooler and the thermometer. None of it tells you whether the vial is usable.

Where This Page Ends and the Others Begin

This page reports what each label states and leaves out. It does not cover gear, cooler math or incident protocol.

• The power is out and the question is the cold chain: keeping pet medication cold when the power goes out.
• What to buy and carry: the insulin cooler and diabetic pet kit guide, which compares cooler classes.
• A room-temperature medication in a hot car: which pet medications fail in a hot car.
• Getting the prescription: emergency and early pet prescription refills and finding veterinary care mid-evacuation.
• The record itself: the pet medication log for evacuation.

Then do the one thing that takes five minutes today and cannot be done in an outage. Take the actual carton out of the refrigerator, find the storage sentence, and copy it word for word onto the card with your veterinarian’s number. If it is a veterinary product, you will be writing down a sentence with no out-of-fridge number in it, and knowing that in advance is worth more than any number a website could give. If it is a human product, write the ceiling down with the day count, because they are one fact and get separated the moment anybody summarizes them.